在C++中实现RGB到HSL的转换

#include <iostream>

struct HSL {
    double hue;
    double saturation;
    double lightness;
};

HSL rgbToHsl(int red, int green, int blue) {
    double r = red / 255.0;
    double g = green / 255.0;
    double b = blue / 255.0;

    double maxVal = std::max({r, g, b});
    double minVal = std::min({r, g, b});

    double h, s, l;
    l = (maxVal + minVal) / 2;

    if (maxVal == minVal) {
        h = 0; // 灰度色
        s = 0;
    } else {
        double d = maxVal - minVal;
        s = l > 0.5 ? d / (2 - maxVal - minVal) : d / (maxVal + minVal);

        if (maxVal == r) {
            h = (g - b) / d + (g < b ? 6 : 0);
        } else if (maxVal == g) {
            h = (b - r) / d + 2;
        } else {
            h = (r - g) / d + 4;
        }

        h *= 60;
    }

    return {h, s, l};
}

int main() {
    int red, green, blue;
    std::cout << "Enter RGB values (0-255): ";
    std::cin >> red >> green >> blue;

    HSL hsl = rgbToHsl(red, green, blue);
    std::cout << "HSL values: H=" << hsl.hue << ", S=" << hsl.saturation << ", L=" << hsl.lightness << std::endl;

    return 0;
}